Foam board

[Penn1974]

I have glued my 2" foam board to my 1x4 boards that are spaced on 16" centers. I have some seams and depressions that I want to fill in to make a smooth surface. Would like to know what filler material to use on the foam. The layout is HO in a bedroom with heat and AC. Would you also paint the foam board ahead of track laying or after track is laid. Thanks in advance.

[the Bach-man]

Dear Penn,
Even if you live on the plains you will see undulations in the terrain.  Keeping the track level and allowing the terrain to vary will add realism to your layout.
Have fun!
the Bach-man

[kh25]

i use wall mud and a putty knife.
mark